target: Add LS1046A

target: Add LS1046A

The LS1046A is a quad-core processor from NXP in the layerscape family.
This SoC is a bit tricky to program: while the AArch64 CPUs are
little-endian, most of the peripherals are big-endian. Care must be
taken when interpreting memory reads/writes. This processor is in the
same family as the ls1012a, so the setup is similar.

If you use OpenOCD to attach early in the boot process, only the cpu0
may be available. Trying to halt other CPUs will fail. To avoid this,
defer examination of cpus 1-3, and provide a core_up helper (like e.g.
zynqmp).

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Change-Id: If5a1a9441fb35fea3e05dc708b42e0cb3bbf2a54
Reviewed-on: https://review.openocd.org/c/openocd/+/6854
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>